Python Coding Challenge - Question with Answer (01091125)

Explanation:

1. List Initialization

nums = [5, 2, 8, 1]

A list named nums is created.

It contains four elements: 5, 2, 8, 1.

2. Initialize Result Variable

r = 0

A variable r is created to store the running total.

It is initially set to 0.

3. Start of the Loop

for i in range(len(nums)):

len(nums) = 4, so range(4) gives: 0, 1, 2, 3.

This loop runs once for each index in the list.

i represents the current index.

4. Update the Result

    r += nums[i] - i

For each index i:

Take the value at that index → nums[i]

Subtract the index → nums[i] - i

Add that result to r

5. Step-By-Step Calculation

i = 0

nums[0] = 5

5 − 0 = 5

r = 0 + 5 = 5

i = 1

nums[1] = 2

2 − 1 = 1

r = 5 + 1 = 6

i = 2

nums[2] = 8

8 − 2 = 6

r = 6 + 6 = 12

i = 3

nums[3] = 1

1 − 3 = −2

r = 12 − 2 = 10

6. Print Final Output

print(r)

Prints the final result.

Output:

10

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